modules/m_chghost.c

   1 /*
   2  * Copyright (c) 2005 William Pitcock <nenolod -at- nenolod.net>
   3  * and Jilles Tjoelker <jilles -at- stack.nl>
   4  * All rights reserved.
   5  *
   6  * Redistribution in both source and binary forms are permitted
   7  * provided that the above copyright notice remains unchanged.
   8  *
   9  * m_chghost.c: A module for handling spoofing dynamically.
  10  */
  11
  12 #include "stdinc.h"
  13 #include "send.h"
  14 #include "channel.h"
  15 #include "client.h"
  16 #include "common.h"
  17 #include "config.h"
  18 #include "ircd.h"
  19 #include "numeric.h"
  20 #include "s_conf.h"
  21 #include "s_newconf.h"
  22 #include "s_serv.h"
  23 #include "s_user.h"
  24 #include "hash.h"
  25 #include "msg.h"
  26 #include "parse.h"
  27 #include "modules.h"
  28 #include "whowas.h"
  29 #include "monitor.h"
  30
  31 static const char chghost_desc[] = "Provides commands used to change and retrieve client hostnames";
  32
  33 static void me_realhost(struct MsgBuf *, struct Client *, struct Client *, int, const char **);
  34 static void ms_chghost(struct MsgBuf *, struct Client *, struct Client *, int, const char **);
  35 static void me_chghost(struct MsgBuf *, struct Client *, struct Client *, int, const char **);
  36 static void mo_chghost(struct MsgBuf *, struct Client *, struct Client *, int, const char **);
  37
  38 struct Message realhost_msgtab = {
  39         "REALHOST", 0, 0, 0, 0,
  40         {mg_ignore, mg_ignore, mg_ignore, mg_ignore, {me_realhost, 2}, mg_ignore}
  41 };
  42
  43 struct Message chghost_msgtab = {
  44         "CHGHOST", 0, 0, 0, 0,
  45         {mg_ignore, mg_not_oper, {ms_chghost, 3}, {ms_chghost, 3}, {me_chghost, 3}, {mo_chghost, 3}}
  46 };
  47
  48 mapi_clist_av1 chghost_clist[] = { &chghost_msgtab, &realhost_msgtab, NULL };
  49
  50 DECLARE_MODULE_AV2(chghost, NULL, NULL, chghost_clist, NULL, NULL, NULL, NULL, chghost_desc);
  51
  52 /* clean_host()
  53  *
  54  * input        - host to check
  55  * output       - false if erroneous, else true
  56  * side effects -
  57  */
  58 static bool
  59 clean_host(const char *host)
  60 {
  61         int len = 0;
  62         const char *last_slash = 0;
  63
  64         if (*host == '\0' || *host == ':')
  65                 return false;
  66
  67         for(; *host; host++)
  68         {
  69                 len++;
  70
  71                 if(!IsHostChar(*host))
  72                         return false;
  73                 if(*host == '/')
  74                         last_slash = host;
  75         }
  76
  77         if(len > HOSTLEN)
  78                 return false;
  79
  80         if(last_slash && IsDigit(last_slash[1]))
  81                 return false;
  82
  83         return true;
  84 }
  85
  86 /*
  87  * me_realhost
  88  * parv[1] = real host
  89  *
  90  * Yes this contains a little race condition if someone does a whois
  91  * in between the UID and REALHOST and use_whois_actually is enabled.
  92  * I don't think that's a big problem as the whole thing is a
  93  * race condition.
  94  */
  95 static void
  96 me_realhost(struct MsgBuf *msgbuf_p, struct Client *client_p, struct Client *source_p,
  97         int parc, const char *parv[])
  98 {
  99         if (!IsPerson(source_p))
 100                 return;
 101
 102         del_from_hostname_hash(source_p->orighost, source_p);
 103         rb_strlcpy(source_p->orighost, parv[1], sizeof source_p->orighost);
 104         if (irccmp(source_p->host, source_p->orighost))
 105                 SetDynSpoof(source_p);
 106         else
 107                 ClearDynSpoof(source_p);
 108         add_to_hostname_hash(source_p->orighost, source_p);
 109 }
 110
 111 static bool
 112 do_chghost(struct Client *source_p, struct Client *target_p,
 113                 const char *newhost, int is_encap)
 114 {
 115         if (!clean_host(newhost))
 116         {
 117                 sendto_realops_snomask(SNO_GENERAL, is_encap ? L_ALL : L_NETWIDE, "%s attempted to change hostname for %s to %s (invalid)",
 118                                 IsServer(source_p) ? source_p->name : get_oper_name(source_p),
 119                                 target_p->name, newhost);
 120                 /* sending this remotely may disclose important
 121                  * routing information -- jilles */
 122                 if (is_encap ? MyClient(target_p) : !ConfigServerHide.flatten_links)
 123                         sendto_one_notice(target_p, ":*** Notice -- %s attempted to change your hostname to %s (invalid)",
 124                                         source_p->name, newhost);
 125                 return false;
 126         }
 127         change_nick_user_host(target_p, target_p->name, target_p->username, newhost, 0, "Changing host");
 128         if (irccmp(target_p->host, target_p->orighost))
 129         {
 130                 SetDynSpoof(target_p);
 131                 if (MyClient(target_p))
 132                         sendto_one_numeric(target_p, RPL_HOSTHIDDEN, "%s :is now your hidden host (set by %s)", target_p->host, source_p->name);
 133         }
 134         else
 135         {
 136                 ClearDynSpoof(target_p);
 137                 if (MyClient(target_p))
 138                         sendto_one_numeric(target_p, RPL_HOSTHIDDEN, "%s :hostname reset by %s", target_p->host, source_p->name);
 139         }
 140         if (MyClient(source_p))
 141                 sendto_one_notice(source_p, ":Changed hostname for %s to %s", target_p->name, target_p->host);
 142         if (!IsServer(source_p) && !IsService(source_p))
 143                 sendto_realops_snomask(SNO_GENERAL, L_ALL, "%s changed hostname for %s to %s", get_oper_name(source_p), target_p->name, target_p->host);
 144         return true;
 145 }
 146
 147 /*
 148  * ms_chghost
 149  * parv[1] = target
 150  * parv[2] = host
 151  */
 152 static void
 153 ms_chghost(struct MsgBuf *msgbuf_p, struct Client *client_p, struct Client *source_p,
 154         int parc, const char *parv[])
 155 {
 156         struct Client *target_p;
 157
 158         if (!(target_p = find_person(parv[1])))
 159                 return;
 160
 161         if (do_chghost(source_p, target_p, parv[2], 0))
 162         {
 163                 sendto_server(client_p, NULL,
 164                         CAP_EUID | CAP_TS6, NOCAPS, ":%s CHGHOST %s %s",
 165                         use_id(source_p), use_id(target_p), parv[2]);
 166                 sendto_server(client_p, NULL,
 167                         CAP_TS6, CAP_EUID, ":%s ENCAP * CHGHOST %s :%s",
 168                         use_id(source_p), use_id(target_p), parv[2]);
 169         }
 170
 171         return;
 172 }
 173
 174 /*
 175  * me_chghost
 176  * parv[1] = target
 177  * parv[2] = host
 178  */
 179 static void
 180 me_chghost(struct MsgBuf *msgbuf_p, struct Client *client_p, struct Client *source_p,
 181         int parc, const char *parv[])
 182 {
 183         struct Client *target_p;
 184
 185         if (!(target_p = find_person(parv[1])))
 186                 return;
 187
 188         do_chghost(source_p, target_p, parv[2], 1);
 189 }
 190
 191 /*
 192  * mo_chghost
 193  * parv[1] = target
 194  * parv[2] = host
 195  */
 196 /* Disable this because of the abuse potential -- jilles
 197  * No, make it toggleable via ./configure. --nenolod
 198  */
 199 static void
 200 mo_chghost(struct MsgBuf *msgbuf_p, struct Client *client_p, struct Client *source_p,
 201         int parc, const char *parv[])
 202 {
 203 #ifdef ENABLE_OPER_CHGHOST
 204         struct Client *target_p;
 205
 206         if(!IsOperAdmin(source_p))
 207         {
 208                 sendto_one(source_p, form_str(ERR_NOPRIVS),
 209                            me.name, source_p->name, "admin");
 210                 return;
 211         }
 212
 213         if (!(target_p = find_named_person(parv[1])))
 214         {
 215                 sendto_one_numeric(source_p, ERR_NOSUCHNICK,
 216                                 form_str(ERR_NOSUCHNICK), parv[1]);
 217                 return;
 218         }
 219
 220         if (!clean_host(parv[2]))
 221         {
 222                 sendto_one_notice(source_p, ":Hostname %s is invalid", parv[2]);
 223                 return;
 224         }
 225
 226         do_chghost(source_p, target_p, parv[2], 0);
 227
 228         sendto_server(NULL, NULL,
 229                 CAP_EUID | CAP_TS6, NOCAPS, ":%s CHGHOST %s %s",
 230                 use_id(source_p), use_id(target_p), parv[2]);
 231         sendto_server(NULL, NULL,
 232                 CAP_TS6, CAP_EUID, ":%s ENCAP * CHGHOST %s :%s",
 233                 use_id(source_p), use_id(target_p), parv[2]);
 234 #else
 235         sendto_one_numeric(source_p, ERR_DISABLED, form_str(ERR_DISABLED),
 236                         "CHGHOST");
 237 #endif
 238 }
 239